The present invention relates generally to mobile communication networks and more particularly, to mobile communication networks having a distributed architecture.
Most radio access networks (RANs) employed today use a hierarchical network architecture in which each higher level entity supports multiple lower level entities. HRPD networks according to the Third Generation Partnership Project 2 (3GPP2) standard exemplify this type of hierarchical network. In HRPD networks, a packet control function performing session control and mobility management functions connects multiple base station controllers (also known as access node controllers) to the core network. Each base station controller, in turn, connects to multiple radio base stations and performs radio resource control functions. The radio base stations communicate over the air interface with the mobile stations. This conventional hierarchical architecture has worked well for voice services and most packet data services.
Recently, there has been some interest in developing a distributed RAN architecture in which the radio base station, base station controller, and packet control function are integrated into a single network entity with a connection to the PDSN. These all-in-one nodes help reduce the amount of hardware in the network by taking advantage of spare processing capacity in the radio base station. In the new distributed architecture, functions traditionally performed by centralized nodes, such as session management and mobility management, are distributed among a plurality of network nodes. Thus, a distributed architecture requires coordination between nodes to perform functions such as session management and mobility management.